Convert Cubic kilometres per year to Acre-feet per day
Convert Cubic kilometres per year (km³/yr) to Acre-feet per day (ac-ft/d) instantly and accurately.
Conversion Formula
ac-ft/d = km³/yr × 2219.611756
About Cubic kilometres per year
The cubic kilometre per year (km³/yr) equals 10⁹/(365.25×86400) ≈ 31.688 m³/s, the unit used in global hydrology, glaciology, and climate science for river basin runoff, ice-sheet mass balance, and groundwater storage change. Total global freshwater river runoff is ≈37 000 km³/yr; the Amazon alone contributes ≈6 600 km³/yr; the Greenland ice sheet loses ≈280 km³/yr to melt and calving. 1 km³/yr ≈ 31.69 m³/s.
About Acre-feet per day
The acre-foot per day (ac-ft/d) equals 1233.48183754752/86400 ≈ 0.014278 m³/s, the practical unit for daily water-delivery scheduling in western US irrigation districts and river-compact administration. Water rights in the Colorado River system are specified in acre-feet per year; daily delivery schedules convert to ac-ft/d. A moderate-size irrigation lateral delivers 5-50 ac-ft/d. 1 ac-ft/d ≈ 0.014278 m³/s ≈ 504.2 US gal/min.
Quick Reference Table
| Cubic kilometres per year (km³/yr) | Acre-feet per day (ac-ft/d) |
|---|---|
| 1 km³/yr | 2219.61 ac-ft/d |
| 2 km³/yr | 4439.22 ac-ft/d |
| 5 km³/yr | 11098.1 ac-ft/d |
| 10 km³/yr | 22196.1 ac-ft/d |
| 25 km³/yr | 55490.3 ac-ft/d |
| 50 km³/yr | 110981 ac-ft/d |
| 100 km³/yr | 221961 ac-ft/d |